Genetic determinants of weed control in rice (Oryza sativa L.) using allelopathy approach

Weed management through herbicide is costing economically and environmentally. Developing of improved weed-suppressive rice genotypes is one of the ultimate goals of rice breeders for sustainable cultivation. In the current investigation, we evaluated the weed-suppressive potential of different rice genotypes and the genetic behind transmitting this ability to their progeny. To achieve this goal, a half diallel mating system was designed and conducted to generate F1 hybrids from six genotypes. Among these genotypes a previously developed allelopathic-resistant pre-breeding advanced lines, the F1 crosses along with their parents were cultivated under weed stress and normal field condition during the 2022 summer growing season. Several vegetative, allelopathic, yield and physio-biochemical traits were studied. The results indicate that the crosses AL1/Sakha Super 300 and AL2/Sakha Super 300 have the highest yield under weed stress condition. AL1, AL2 and Sakha Super 300 have the highest general combining ability for yield and allelopathic characters under weed stress. Furthermore, the cross AL2/Sakha Super 300 ranked the highest based on the stress tolerance indices. High positive correlation was detected between grain yield and the most studied physio-biochemical characteristics. This investigation provides evidence of the potential of enhancing the allelopathic activity of rice crop through precise selection of parental genotypes.